An electronic component package refers to a type of package technology for electrically connecting an electronic component to a printed circuit board (PCB), for example, a main board of an electronic device, or the like, and protecting the electronic component from external impacts, which is distinguished from a technology of embedding an electronic component in a printed circuit board, for example, an interposer substrate. Meanwhile, a major recent trend in the development of technology related to electronic components has been to reduce the size of electronic components. Therefore, in the field of package technology, in accordance with a rapid increase in demand for a small electronic component, or the like, implement an electronic component package having a small size and including a plurality of pins has been demanded.
As a type of package technology suggested in order to satisfy the technical demand as described above, a wafer level package (WLP) using a redistribution wiring of an electrode pad of an electronic component formed on a wafer has been suggested. An example of such a wafer level package includes a fan-in wafer level package and a fan-out wafer level package. Particularly, the fan-out wafer level package has a small size and is advantageous in implementing a plurality of pins. Therefore, recently, the fan-out wafer level package has been actively developed.
Meanwhile, generally, in a case in which the electronic component package is mounted on the main board of the electronic device, or the like, since a difference between coefficients of thermal expansion (CTEs) of the electronic component and the main board is significantly high, a difference between effective coefficients of thermal expansion of the electronic component package and the main board is intensified. As a result, in a case in which the electronic component package mounted on the main board is exposed to a harsh environment, a crack may be generated in a connection terminal, for example, a solder ball, connecting the electronic component package and the main board to each other.